Dynamo-electric machine.



H. LIIPELT.

DYNAHO ELEUTBIG MACHINE.

APPLIOATIOH FILED FEB. a, 1908.

Patented Apr. 2'7, 1909.

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A TTK EL LIPPELT,

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED FEB. a, 1908.

Paqfientad Apr. 27, 1909.

5 SHEETS-SHEET 2.

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PPTZ'TNESEES/ INYENTUH axsk HANS -E' m BY W H. LIPPELT.

DYNAMO ELECTRIC HAGEINE.

APPLIOATIOH FILED r52. s, 1908.

5 SHEETS-SHEET 3.

JNVENTUR HANS r LZ'FFE'L T.

H.. LIPPELT.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED IEB.3,-190B.

9 1 9,604, Patented A101. 2'7, 19.09.

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DYNAMO ELECTRIC MACHINE. APPLIOATION FILED FEB. s, 1908.

919,604, PatentedA 7,1909.

WI TNESSES: v INS/ENTER.

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AT TYT iuvirnn STATESPATENT oniuon.

HAN-S LIPPELT, OF LYNN, MAS 'AGHUSETTS, ASSIGNQR T0 GENERAL ELEGTRI A CORPORATION OF NEW YORK.

DYNAMG- ELECTRIC MACHINE.

Specification of Letters Zatent.

Patented April 27, 1909.

T 0 all whom it may concern:

Be it known that I, Hans LirPELT, a subject of the Emperor of Germany, residing at Lynn, in the county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a specifica- 'tion. F

' My invention relates to dynamo-electric machines, and consists in an improvement in the machine described in Patent No. 75Q,793, issued to me April 5, 1904. In that -patent I described a dynamoelectrici machine having an armature of the open-coil; type with commutator and'brushes arranged to maintain each armature-coil in circuit while cutting the flux of the field-clesnthe field-magnet being arranged to give a substantially uniform induced voltage in the armature conductors as they pass the fieldpol'es both under'load and at no-load. My

invention has to do with the commutation of such a machine, and comprises a number of features which will be specifically pointed out in the appended claims, but will best he understood by reference to the accompanying drawings, in whic Figure 1 shows diagrammatically an end viewof a machine arranged in accordance with my invention, both armature and field being developed along a straight line; Fig. 2 shows a diagrammatic plan view of the armature, the windings and commutator being develo ed on a plane surface; Fig. 3 shows a soniew lat diagrammatic end view of the machine; Fig. 4 is an explanatory diagram of the positions of the poles; Fig. 5 is adiagram of the induced. voltages in the armature conductors in a generator; Figs. '6 and? are explanatory diagiams; Fig. 8 is a diagram of induced armature voltages in a motor; Fig. 9 shows an end elevation of one of the main field poles; Fig. 10 shows a side eleva tion of the same; Fi 11 shows an end elevation of a modified rm of one of the main poles with the windings in cross-section; ig'. 12 is a similar view of one of the auxiliary poles; Fig. 13 shows a modifiedarrange ment of the reactive coil employed for commutation purposes; and Fig. 14 is a crosssectional view of the reactive coil suitably arranged. Referrin first to Fig. 1, 1, 2, 3, l, 5 and '6 represent t e mi; in field-poles, which are unevenly spaced, and 7 and 8 represent auxil.

iary poles occupying the spaces left by the uneven spacing of the mam poles. The auX- communicating poles 7, and the auxiliary pole 8 1S smnlarly arranged. 9 represents a shunt winding magnetizing each 01' the main poles. The direction of current in the conductors of this winding is indicated in the conventional manner, and the polarities of the main poles due to the shunt winding are indicated by the letters N and S. 10 represents a series'winding which surrounds a l or a portion of the main poles, and which, it will be noted, op oscs the shunt winding on certain poles an assists it on others. This sericswinding also magnetizes the auxiliary .poles 7 and '8, a single coil serving to magnetize both the cornmutating poles formed by each auxiliary pole. The armature winding is oi the open-coil type, as shown in Fig. 2, and comprises four coils, or rather fourcircuits of three coils each, l1, 12, 13 and 14. it will be understood that in practicca larger number of circuits or sets of coils may be employed, but four are sufficient for purposes of illustration. In Fig. l the directions of current-flow inthe armature conductors are indicated conventionally, and it will be seen that three of the four sets of coils are in cir cult. For cutting the armature coils into and out of circuit, brushes 15 and comn1uta tor segments 16 are provided. If the armature conductors are stationary they are connected to the brushes 15., while the commutator segments 16 are connected to collector rings 17, from which the armature current is led off by brushes 18. It will be noted that half the segments 16 have their ends 16 separated from the main portion of the segment, so as to form small auxiliary se mcnts. This arrangement of segments and o? the re active coil 19, to which the segments are connected, are for purposes of commutation, as will be ex lained hereinafter.

Fig. '3 rows an end elevation of the machine, which figure will be understood from the above description of Figs. 1 and 2. The direction of rotation of the field-magnet, in the case of a generator, is indicated by the arrow.

It will be seen that the spacing of the main field-poles with respect to any one armature circuit is uneven. If any armature circuit is traced from one brush 15 through the C('llconductors to the brush which forms the 0 COMPANY,

iliary po e 7 is bifurcated so as to form two the c t ar indicated erpositionas for a single coil, the result will Be as indicated in Fig. i, From this figure it is seen that the main poles 1, 3 5,displace i as liown, form in effecta resultant north pole .nagnetized the shunt Hurling 9. The winding on the s 1 and 5' tends e produce a cross mag tion of the re *nltant pole formed by the three poles 1, 3 and 5, and if this series Winding is propefly it will neat-e for armawhich tends to produce an opiagnetization thepole, or in ids Wei lion poie 1 and to ii-dill ion to the turns tne W'Jz'iding 10 coma the coinmutating s and 8, which lie the tips of the zit pc mined by the irce poles 1, 3 and ,7 sale a norm pole, while the pole 11h pole, s

' is to increase i ,i. ole at one tip and Wes if, now, we consider the v induced in a conductor under the resu pole formed by 1e main poles 1, 3 and 5 and the commutat- 39 i 7, which velages will be e actual; the

-circu it, it

i h ir- 35 1m Q; s 111g caused by 1g poles, indiese poles were would lines 20. I 22, above o, represents inals, the

1 me nuxor me 0011111111 cated by" the mnves 2-3, i; abs. t,=tl1e top of-tlio on. straight as indicated in (lQb it The distance between the H and oelmvv the aro-line of rage- .he 2' 'n cet the top of r t 6 rep io-drop in the armature. vil J voltages induced. by 0011111111 les are to the voltage-drop the armature, but

' one n is is added to ll'l pores; and

A e other commain poles. a armature voles 4 L loads. Tl

, 2C8 bk) eurrei that the effect eiaece the vertical lines 23 and 24, respectively. The curve 25 then represents the rise and fall of current in the conductor passing under the pole. "When a coil is first cut into. the circuit, the current does not rise instantanc T0 ousiy to its full value, on account of self-induction; but rises as shown by the curve 25. When the coil conductors reach the point 26,

at which the induced voltage begins to fall, the current also begins to fali; and after pass 3 ing the point 27, at which the induced voltags is equal to the voltage at the armature terminals, the current in the coil falls more rapidly, becoming zero at the line If the coil cut out oi circuit exactl t the point so indicated bythe line 24, no sparl ing will rcsult, because the current in the conductor at that instant is at zero; but in practice it is impossible to maintain this point exactly. it is shifted more or less by arnn-iture reaction with 'va'iaticns in load, so that ordithe coil will be cut out circuit on one side or the other of the point indicated by the line 24. Since the wurront tends to vary rapidly in the coil on t on side oi this so line, a brush-adjustment at is faulty comparatively small degree will produce sparking.

Fig. 7 shows the current in an armatureccii with curve of induced. voltage the same entering-end, the

0 6. 1 in Fig. 5.

induced in 1 1'1 theiield. At t e outgoing-end the curve 25 is of a lifferen shape from tha ct Fig, G. Since -t -e induced voltage at outgoing end falls oil abruptly anc ent then is imifcrm for a eel-lain ar-gtt. time, w a 'r 7 L a tne current-curve 2e tails at inst,

this latter line he currentin in. is small. 13% Therefore, owing to the peculiar film-distrili-ution, no adjustment of tl EShEflWitil J detector fixefllaz'usilee The curves above described reie machine rimming as a generator.

runs as a motor, vol (iicated by Fig.6. in this cs. v terminabvcltage is in excess of V rmatnrc voltege by as amount equal to the ohmic-drop in the armature, and field is strengthened by the conmintati g5; poles at re outgoin" pole-tip and wee for a s cit-time after it enters era-e04 In order toidecrease the self-induction of the end of the poleat which the armaturecoil is cut out of circuit. This construction offers a high reluctance to the flux due to the armature current, and consequently gives to the armature-coils a lowreactance.

Fig. 10.shows a side view ofapole constructed as in Fig. 9.

'The compensation of armature. reactance .by series windings on the unevenly distributed main poles has already been described. This arrangement is efli'ective in neutralizing armature reaction on the resultant pole formed'by the severalunevenly spaced poles. Kit is desired to cerii ensate for armature reaction on each individual pole, it. may be done in the manner shown in Fig. 11. In this figure, in addition to the main shuntcoils 9- and series coiis 10, auxiliary coils 32 are embedded in the pole near its face and the, coils 14 will be cut into circuit.

' ed means or thisconnection the decrease in our: rant-1n thec'o'iis 11, as they pass out from the connected so as to tend to cross-magnetize the pole-face, therebyopposing the crossmagnetizing'tendency oi the armature current.

oiie of the auxiliary poles forming a pair of commutating poles magnetized by a signal series coil 10. Armatune reaction on the Now referring again to Fig. 2, the opera-- tion of the reactive coil 19, which has already been referred to,.will be explained. In Fig.

2 this coil is shown inserted in the connection between one of the collector rings 17 and the commutator segments connected to this collector ring. One terminal of the coil is connected to the main commutator segment 16, while other terminals are connected to the auxiliary segments 16. If the commutator-in Fig; 2'is"supposed to be moving coils 11 will next be cut out of circuit, while v It will further be seen'that one of the brushes 15, connected to the coils 11, will reach oneoi the auxiliary commutator se ents 16 at the same time that one of. t .ese auxiliary segments is reached b a brush connected to the coils 14. The cois 11 and 14 are conse quently simultaneously connected to the reactive device 19, and, in fact, are connectin parallel through this device.

Fig. 12 shows a suitable construction for field-poles inducesin the reactive windinga voltage which tends toassist the use in current in the coils 14 as they are cut into c1r cuit, while the rise of current in the coils 1 all to the main commutator segment 1.6, but

may be connected as shown in. Fig. 13. The

operation is substantially the same as has been described in connectionwith Fig. 2.

The reactive coil may conveniently be mounted on the shaft of the machine be tween the commutator and the collector rings 17, as is indicated in Fig. 14.

I'd'o not desire to limit myself to the par ticular construction and arrangement, of parts here shown, but aim inthe appended claims to cover all modifications which are within the scope of my invention.

What I claimas new and desire to secure by Letters Patent oi the United States,is

1. In a dynamo-electric machine, a multipolar field-magnet, an armature having a winding of the open-coil type, and a commutator and brushes for the armature winding arranged to maintain each coil in circuit whileitis cutting the flux of the field-poles,, said magnet having v main poles unevenly .spaced with respect to the armature winding and rovided with both shunt and series windings and auxiliary commutating poles occupying the spaces left by the uneven spaclng of the main poles and provided with series windin'gsx 2. In a dynamo-electric machine, a multipolar field-magnet, an armature having winding of the open-coil type, and a commutator and brushes for the armature winding arranged to maintain each coil in circuit while it is cutting the flux of the field-poles,

said magnet having main" poles unevenly spaced with respect to the armature winding from left to right, -1t will be seen that the and provided with both shuntand series coils and auxiliary commutating poles occupying the spaces left by the uneven spacing of the main poles and provided with series windngs, the series winding on the main poles be- 111g connected to oppose the shunt winding on some of said poles and to resist it on others,

circuit While it is cutting the flux of the fieldpoles, a reactive device, and connections between said device and the commutator and brushes whereby the armature coils about to be cut out of circuit and the coils about to be cut into circuit are simultaneously connected to said reactive device.

4. In a dynamo-electric machine, a fieldmagnet, a field Winding thereon, an armature having a Winding of the open-coil type, a commutator and brushes for the armature winding arranged to maintain each coil in circuit While it is cutting the flux of the field-poles, a reactive device, and connections between said device and the commutator and brushes whereby the armature coils to be cut out of circuit and the coils about to be out into circuit are simultaneously connected in parallel through said readapted to induce in each armature coil a substantially uniform voltage of a certain arnount during the greater part of the tune it is in clrcuit and a substantially uniform Witnesses:

erases voltage of a different amount for a email part into circuit are simultaneously connected to said reactive device} 6. In a dynamo-electric machine, a multipolar field-magnet, an armature having a Winding of the open-coil type, and a commutator and brushes for the armature Winding arranged to maintain each coii in circuit While it is cutting the fiux of the field-poles,

said magnet having main poles unevenly spaced With respect to the armature Winding and provided with main exciting windings and auxiliary poles occupying the spaces left by the uneven spacing of the main poles nd bifurcated so that each auxiliary pole forms a pair of commutating oles, and a seriesconnected coil surroun ing each auxiliary pole and magnetizing both of the commutating poles formed thereby.

In witness whereof, I have hereunto set my hand this twenty-ninth day of January,

' HANS LIPPELT.

JOHN A. MOMANUS, Jr., ALEXANDER M. GILBERT. 

